Tshilenge Georges Mbuyi, Dundon William G, De Nardi Marco, Mulumba Mfumu Leopold K, Rweyemamu Mark, Kayembe-Ntumba Jean-Marie, Masumu Justin
Faculty of Veterinary Medicine, University of Kinshasa, University Street, P.O. Box 117, Kinshasa XI, Democratic Republic of the Congo.
Central Veterinary Laboratory, Wangata Street, Gombe, P.O. Box 8842, Kinshasa, Democratic Republic of the Congo.
Trop Anim Health Prod. 2019 Mar;51(3):537-543. doi: 10.1007/s11250-018-1721-5. Epub 2018 Oct 22.
This study aimed at assessing the serological and virological status of Rift Valley fever virus (RVFV) in cattle from four climatically diverse zones of the Democratic Republic of the Congo (DRC). A total of 1675 sera samples collected between 2014 and 2015 from cattle without clinical manifestation of RVF infection were tested using competitive and capture enzyme ELISA to detect both IgG and IgM. RT-PCR was used for the detection of nucleic acid of RVFV. Out of the 1675 cattle sera tested, 203 were found to be IgG-positive, giving an overall true seroprevalence of 12.37% (95% CI 10.86-14.05). This seroprevalence varied between the four zones with a seroprevalence of 16.16% (95% CI 12.86-20.12), 14.70% (95% CI 11.72-18.29), 10.82% (95% CI 7.19-14.19), and 7.34% (95% CI 5.13-10.41) recorded in cattle sampled in the mountainous, humid savannah, dry savannah, and forest zones, respectively (p < 0.05, χ = 17.26). A higher true seroprevalence of 14.58% (95% CI 9.3-22.13) was found in animals aged 1 year compared to 10.43% (95% CI 8.12-13.30) and 13.16% (95% CI 11.19-15.42) in groups aged between 2-3 and > 3 years, respectively, although the difference was not statistically significant (p > 0.05, χ = 2.95). Similarly, no statistically significant difference (p > 0.05, χ = 0.04) was found between the sexes of the animals. Among the IgG-positive samples screened for anti-RVFV IgM, only 1.47% (3/203) was IgM-positive. One of the IgM-positive samples was positive by RT-PCR. These findings reveal country-wide distribution of RVF in the DRC for the first time.
本研究旨在评估刚果民主共和国（DRC）四个气候多样地区牛群中裂谷热病毒（RVFV）的血清学和病毒学状况。2014年至2015年期间，从无裂谷热感染临床表现的牛群中总共采集了1675份血清样本，使用竞争法和捕获酶联免疫吸附测定法检测IgG和IgM。逆转录聚合酶链反应（RT-PCR）用于检测RVFV的核酸。在检测的1675份牛血清中，发现203份IgG呈阳性，总体真实血清阳性率为12.37%（95%置信区间10.86 - 14.05）。四个地区的血清阳性率各不相同，山区、湿润稀树草原、干燥稀树草原和森林地区采样的牛群血清阳性率分别为16.16%（95%置信区间12.86 - 20.12）、14.70%（95%置信区间11.72 - 18.29）、10.82%（95%置信区间7.19 - 14.19）和7.34%（95%置信区间5.13 - 10.41）（p < 0.05，χ = 17.26）。1岁龄动物的真实血清阳性率较高，为14.58%（95%置信区间9.3 - 22.13），而2 - 3岁龄组和大于3岁龄组分别为10.43%（95%置信区间8.12 - 13.30）和13.16%（95%置信区间11.19 - 15.42），尽管差异无统计学意义（p > 0.05，χ = 2.95）。同样，动物性别之间未发现统计学显著差异（p > 0.05，χ = 0.04）。在筛选的抗RVFV IgM的IgG阳性样本中，只有1.47%（3/203）为IgM阳性。其中一份IgM阳性样本通过RT-PCR检测呈阳性。这些发现首次揭示了RVF在刚果民主共和国的全国性分布。
